An endoscope is a medical device that is mainly intended to observe inside the human body. An optical system is installed inside a barrel of the endoscope, and a tip of the barrel is inserted into the human body to display an image inside the human body on a monitor. In recent years, a laser endoscope in which a laser therapeutic device is installed in the endoscope has particularly attracted attention as a new cancer treatment. In the treatment, cancer is normally removed roughly by a conventional endoscopic surgery and remaining cancer cells are then completely extinguished by irradiating the removed area with a laser beam of the laser endoscope.
Further, in the case where a tumor is relatively small and not deeply invading into the tissue, it has also been attempted without carrying out an endoscopic surgery to destroy cancer cells solely by hyperthermia with the laser endoscope. The hyperthermia (thermal therapy for cancers) is a treatment which heats a tumor locally at a temperature of 42° C. or more for 30 to 60 minutes. The hyperthermia not only kills cancer cells, it is also expected to improve by heating the immune function of normal cells as well as the effect of radiation and chemotherapy.
In endoscopic operations, depending on their method and purpose, a rigid endoscope having a rigid bar-like barrel or a flexible endoscope having a barrel made of a flexible tube is selectively used. Though the laser therapeutic device of the present invention is mainly installed in a rigid endoscope, miniaturization thereof enables itself to be installed also in a flexible endoscope.
As for types of endoscope, there are an optical type in which a plurality of lenses is stored in the barrel and an electronic type in which a camera unit of a CCD image sensor is arranged at the tip of the barrel. An illumination unit (an external light introduction type or an LED emission type) capable of emitting intensive light is provided at the tip of the barrel. There is also an endoscope provided with an operation tool for surgery, and for example, Patent Literature 1 (U.S. Pat. No. 4,836,189) is known to disclose a hysteroscope including a laser scalpel.